Abstract
Since the last IAEA-FEC in 2021, significant progress on the development of long pulse steady state scenario and its related key physics and technologies have been achieved, including the reproducible 403 s long-pulse steady-state H-mode plasma with pure radio frequency (RF) power heating. A thousand-second time scale (∼1056 s) fully non-inductive plasma with high injected energy up to 1.73 GJ has also been achieved. The EAST operational regime of high βP has been significantly extended (H98y2 > 1.3, βP ∼ 4.0, βN ∼ 2.4 and ne/nGW ∼ 1.0) using RF and neutral beam injection (NBI). The full edge localized mode suppression using the n = 4 resonant magnetic perturbations has been achieved in ITER-like standard type-I ELMy H-mode plasmas with q95 ≈ 3.1 on EAST, extrapolating favorably to the ITER baseline scenario. The sustained large ELM control and stable partial detachment have been achieved with Ne seeding. The underlying physics of plasma-beta effect for error field penetration, where toroidal effect dominates, is disclosed by comparing the results in cylindrical theory and MARS-Q simulation in EAST. Breakdown and plasma initiation at low toroidal electric fields (<0.3 V m−1) with EC pre-ionization is developed. A beneficial role on the lower hybrid wave injection to control the tungsten concentration in the NBI discharge is observed for the first time in EAST suggesting a potential way toward steady-state H-mode NBI operation.
Original language | English |
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Article number | ad4270 |
Journal | Nuclear Fusion |
Volume | 64 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1 2024 |
Funding
This work was supported by the National MCF Energy R&D Program (2022YFE03050000, 2019YFE03040000), the US Department of Energy, Office of Science, Office of Fusion Energy Sciences Cooperative Agreement DE-SC0010685, the National Natural Science Foundation of China under Contract Nos. 12375229, 12375230 and 12305254.
Keywords
- EAST tokamak
- ITPA
- steady state long pulse